/Engine/Source/Editor/Kismet/Public/BlueprintCompilationManager.h
Safely reparents all child classes of every Key in OldClassToNewClass to the class in the corresponding Value. Typically this means every child type will be reinstanced - although reinstancing could be avoided when layouts match.
static void ReparentHierarchies ( const [TMap](API\Runtime\Core\Containers\TMap)< [UClass](API\Runtime\CoreUObject\UObject\UClass) *, [UClass](API\Runtime\CoreUObject\UObject\UClass) * > & OldClassToNewClass )